Hi Janos - I think you need to use GPX Track for the Fenix 5, thoiugh you could try TCX to see if that works too. There is a good demo video on YouTube on how to copy a GPX route to a Garmin Fenix 3 or Fenix 5. I'm not sure about the navigation arrows as I don't have one of those devices to check.
What is the best file format to download a planned route to have turn be turn navigation?
How do I copy to my watch?
If I download as gpx what is the difference between track and route? Will that show navigation arrows?
Thank you for your help, sorry i someone asked this already I didn't find relevant topic.